The invention relates to an irrigation system for hydroponic crops, of the type used in growing tanks (1) containing a nutrient solution, and which is formed by a grid (2) partially submerged in the nutrient solution of the growing tank (1), the grid (2) being formed by straight channels (3) separated from each other by adjacent cells (4) in which the plants to be grown are arranged, said cells being connected to the channels (3) and/or to each other, the channels (3) having a cross section in the shape of an inverted U. The system comprises at least one irrigation emitter (5) disposed in a channel (3) of the grid, the emitter (5) being configured to emit a volume of nutrient solution into the nutrient solution contained in the tank (1) or onto the surface (10) of same. The invention also relates to an irrigation method.